MoVast2 combined with MoVast1 regulates lipid homeostasis and autophagy in Magnaporthe oryzae.

Macroautophagy/autophagy is an evolutionarily conserved biological process among eukaryotes that degrades unwanted materials such as protein aggregates, damaged mitochondria and even viruses to maintain cell survival. Our previous studies have demonstrated that MoVast1 acts as an autophagy regulator regulating autophagy, membrane tension, and sterol homeostasis in rice blast fungus. However, the detailed regulatory relationships between autophagy and VASt domain proteins remain unsolved. Here, we identified another VASt domain-containing protein, MoVast2, and further uncovered the regulatory mechanism of MoVast2 in M. oryzae. MoVast2 interacted with MoVast1 and MoAtg8, and colocalized at the PAS and deletion of MoVAST2 results in inappropriate autophagy progress. Through TOR activity analysis, sterols and sphingolipid content detection, we found high sterol accumulation in the ΔMovast2 mutant, whereas this mutant showed low sphingolipids and low activity of both TORC1 and TORC2. In addition, MoVast2 colocalized with MoVast1. The localization of MoVast2 in the MoVAST1 deletion mutant was normal; however, deletion of MoVAST2 leads to mislocalization of MoVast1. Notably, the wide-target lipidomic analyses revealed significant changes in sterols and sphingolipids, the major PM components, in the ΔMovast2 mutant, which was involved in lipid metabolism and autophagic pathways. These findings confirmed that the functions of MoVast1 were regulated by MoVast2, revealing that MoVast2 combined with MoVast1 maintained lipid homeostasis and autophagy balance by regulating TOR activity in M. oryzae.

[Effect and mechanism of total flavonoids of Lichi Semen on CCl_4-induced liver fibrosis in rats, and prediction of Q-marker].

This paper was to investigate the effect of total flavonoids of Lichi Semen(TFL) on carbon tetrachloride(CCl_4)-induced liver fibrosis in rats, analyze and predict its mechanism of action and potential quality markers(Q-marker). Firstly, male SD rats were taken and injected subcutaneously with a 40% CCl_4-vegetable oil solution twice a week for 8 consecutive weeks to establish a rat model of liver fibrosis. The rats with liver fibrosis were randomly divided into model group, silybin group(43.19 mg·kg~(-1)), Fuzheng Huayu Capsules group(462.75 mg·kg~(-1)), and TFL groups(100 mg·kg~(-1) and 25 mg·kg~(-1)), with normal rats as a blank group, 10 rats in each group. Except for the blank group, the rats in the other groups were subcutaneously injected with 40% CCl_4-vegetable oil solution of a maintenance dose, once a week. The rats in various treatment groups received corresponding doses of drugs, while the rats in the blank group and model group received the same volume of normal saline once a day for 4 weeks. At the end of the experiment, blood was collected from the abdominal aorta and the liver tissues were collected. The levels of total bilirubin(TBiL), direct bilirubin(DBiL), indirect bilirubin(IBiL), alanine aminotransferase(ALT), and aspartate aminotransferase(AST) in serum were detected by using an automatic biochemical detector. Masson staining was used to observe the histopathological changes of rat liver. Then, the chemical compositions of TFL were collected, and the action targets of these chemical compositions were predicted through SWISS database and reverse molecular docking server(DRAR-CPI). After screening of disease targets of liver fibrosis by Gene Cards database, the protein-protein interaction was analyzed with use of STRING database, and GO(gene ontology) analysis and KEGG(Kyoto encyclopedia of genes and genomes) enrich analysis were also carried out. Moreover, an iTRAQ proteomics technology was used to determine protein expression in liver tissues of rats in TFL, model and blank groups to verify the targets. Furthermore, Cytoscape software was used to establish and visualize the network of chemical components, targets and pathways, and predict the potential Q-marker of TFL. The results showed that the levels of TBiL, DBiL, IBiL, ALT, and AST in the model group were significantly higher than those in the blank normal group(P<0.05), and the above levels in the treatment groups were lower than those in the model group, but with no significant differences. Masson staining showed that the liver damage and the degree of fibrosis were severe in the model group, and were relieved to different degrees in the treatment groups. Then, 74 chemical components were screened, which could act on 865 targets such as EGFR and SRC, participating in the regulation of cancer pathways, PI3 K-Akt signaling pathway, HIF-1 signaling pathway and other signaling pathways closely related to liver fibrosis. Pinocembrin, quercetin, epicatechin, procyanidin A2, naringenin, nobiletin, phlorizin and rutin showed the highest correlation with liver fibrosis-related targets and pathways. Proteomics results showed that a total of 18 proteins among the 45 proteins predicted by internet pharmacology were identified, among which 6 proteins were significantly expressed, including 5 up-regulated proteins and 1 down-regulated protein. The protein expression of ALB, PLG, HSP90 AA1, EGFR and MAP2 K1 was significantly returned to a normal state in the TFL treatment groups. In conclusion, TFL may demonstrate the anti-hepatic fibrosis and potential hepatoprotective effects by regulating the expression of ALB, PLG, HSP90 AA1, EGFR and MAP2 K1, which may be associated with the regulation of multiple signaling pathways related to liver fibrosis such as PI3 K-Akt pathway. Pinocembrin, quercetin, epicatechin, procyanidin A2, naringenin, nobiletin, phlorizin and rutin could be regarded as potential Q-markers of TFL for quality control.